The ad giant’s chief executive Laura Desmond told the Financial Times that in just a short amount of time, Twitter “has gone from an experiment to something that is essential.”

Starcom buys ads for Walmart, Microsoft, Coca-Cola, and Proctor & Gamble, among others. The deal reportedly gives those companies priority ad slots on Twitter and access to the social network’s data and new products.

Terms of the deal weren’t disclosed, but reportedly the two companies also plan to study how advertisers can better market to television viewers using social media. The effort, called a “social TV lab,” will attempt to analyze the second screen effect. Companies want to know more about the relationship between your TV viewing habits and your tweets. This will help Twitter make money on ads, and advertisers make money off you.

The Financial Times noted that the partnership is not exclusive, so Twitter can strike ink similar deals with other ad companies.

Other ad moves

Reports of the ad deal surfaced just days after unnamed sources told Bloomberg about Twitter’s interest in partnering with Viacom and NBCUniversal to stream content on Twitter and sell ads to go with it.

Twitter last week also rolled out keyword targeting for advertisers, allowing companies to market to users who would be more likely to buy. If you tweet about a TV show, that show’s advertisers might be able to market to you on Twitter, too.

This new push in TV comes as networks prepare their fall schedules and companies jockey for prime ad placement in the newest and hottest shows.

And in a cryptic tweet last week, BBC America said it had inked a deal with Twitter to “offer first in-tweet branded video synced to entertainment TV series.” Whatever that means. No other details about the partnership have been released.